Sonny Bill Williams casts a shadow over the Chiefs, his absence from the 2013 side the key discussion point about the defending champions. Greg Growden argues they'll cope.

Last season: Deserving champions after their balanced squad evolved under the coaching of Dave Rennie and Wayne Smith, each player ranking among the competition's best in their individual positions. The Chiefs boasted the No.4-ranked offence and the No.2-ranked defence, and their 37-6 defeat of the Sharks in the Final - after their 23-19 loss to the Highlanders in round one - was a fair indication of their progress and of their final superiority over all-comers.

Key man: Aaron Cruden was brilliant at fly-half in 2012, scoring a competition-leading 234 points, making 11 linebreaks, nine linebreak assists and nine try assists. But Liam Messam remains the heartbeat of the team, making four linebreaks, scoring four tries, busting 44 tackles, making 154 runs and completing 236 tackles. There is no Cruden and no Chiefs without Messam.

Rising star: Charlie Ngatai failed to crack the Hurricanes' midfield in 2012, having missed much of 2011 with a broken ankle, but Dave Rennie believes he can fill at least some of the Sonny Bill-sized hole at No.12. Ngatai boasts an SBW-esque frame at 103kg and 188cm, and he can also play on the wing and at No.15. He's unlikely to "replace" Williams, but he is likely to make an impact.

Season preview: Their title defence may hinge on their ability to overcome the loss of Sonny Bill Williams, to Japan and rugby league, and of Sona Taumalolo to France after the pair's standout efforts in 2012. But they remain a very balanced squad, and their working man's game plan of hard-working raw-boned players - 1 to 22 - with an emphasis on set piece strength should see them riding high on the ladder throughout the season.

Greg Growden's verdict: Will they be able to survive without Sonny Bill? Williams' involvement was crucial in the Chiefs winning the 2012 title, as his offloads and line busts made him one of Super Rugby's most valuable and dangerous weapons. He's off to the boxing ring, Japan and rugby league, and so the Chiefs have to find someone quick to give their midfield some threat. Dave Rennie, who enjoyed major triumph in his first year in charge, argues there is life after Sonny Bill, but the fact is that Aaron Cruden is under more pressure to perform consistently.